Reference

byte_container_with_subtype

JSON Pointer defines a string syntax for identifying a specific value within a JSON document

ordered_map

a minimal map‐like container that preserves insertion order

json

default specialization

ordered_json

specialization that maintains the insertion order of object keys

Functions

Name

Description

Unnamed overloads

operator>>

Right shift operators

swap

exchanges the values

to_string

user‐defined to_string function for JSON values

operator<<

Left shift operators

Types

Name

Description

adl_serializer

default JSONSerializer template argument

basic_json<>

basic_json

a class to store JSON values

an internal type for a backed binary type

byte_container_with_subtype<vector<unsigned char>>

JSON Pointer defines a string syntax for identifying a specific value within a JSON document

ordered_map

a minimal map‐like container that preserves insertion order

json

default specialization

ordered_json

specialization that maintains the insertion order of object keys

Functions

Name

Description

Unnamed overloads

operator>>

Right shift operators

swap

exchanges the values

to_string

user‐defined to_string function for JSON values

operator<<

Left shift operators

Synopsis

Declared in <nlohmann/json_fwd.hpp>

using json = basic_json;

specialization that maintains the insertion order of object keys

Synopsis

Declared in <nlohmann/json_fwd.hpp>

using ordered_json = basic_json<ordered_map>;

default JSONSerializer template argument

Synopsis

Declared in <nlohmann/adl_serializer.hpp>

template<
    typename T = void,
    typename SFINAE = void>
struct adl_serializer;

Static Member Functions

Name

Description

from_json

convert a JSON value to any value type

to_json

convert any value type to a JSON value

Description

This serializer ignores the template arguments and uses ADL([argument‐dependent lookup](https://en.cppreference.com/w/cpp/language/adl))for serialization.

convert a JSON value to any value type

Synopses

Declared in <nlohmann/adl_serializer.hpp>

convert a JSON value to any value type

template<
    typename BasicJsonType,
    typename TargetType = ValueType>
static
decltype(::nlohmann::from_json(std::forward<BasicJsonType>(j), detail::identity_tag<TargetType> {}))
from_json(BasicJsonType&& j) noexcept(noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), detail::identity_tag<TargetType>{})));

convert a JSON value to any value type

template<
    typename BasicJsonType,
    typename TargetType = ValueType>
static
decltype(::nlohmann::from_json(std::forward<BasicJsonType>(j), val), void())
from_json(
    BasicJsonType&& j,
    TargetType& val) noexcept(noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val)));

default_object_comparator_t

convert a JSON value to any value type

Synopsis

Declared in <nlohmann/adl_serializer.hpp>

template<
    typename BasicJsonType,
    typename TargetType = ValueType>
static
decltype(::nlohmann::from_json(std::forward<BasicJsonType>(j), detail::identity_tag<TargetType> {}))
from_json(BasicJsonType&& j) noexcept(noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), detail::identity_tag<TargetType>{})));

convert a JSON value to any value type

Synopsis

Declared in <nlohmann/adl_serializer.hpp>

template<
    typename BasicJsonType,
    typename TargetType = ValueType>
static
decltype(::nlohmann::from_json(std::forward<BasicJsonType>(j), val), void())
from_json(
    BasicJsonType&& j,
    TargetType& val) noexcept(noexcept(::nlohmann::from_json(std::forward<BasicJsonType>(j), val)));

convert any value type to a JSON value

Synopsis

Declared in <nlohmann/adl_serializer.hpp>

template<
    typename BasicJsonType,
    typename TargetType = ValueType>
static
decltype(::nlohmann::to_json(j, std::forward<TargetType>(val)), void())
to_json(
    BasicJsonType& j,
    TargetType&& val) noexcept(noexcept(::nlohmann::to_json(j, std::forward<TargetType>(val))));

Synopsis

Declared in <nlohmann/json.hpp>

template<>
class basic_json<>
    : public nlohmann::detail::json_base_class<void>

Base Classes

Name

Description

nlohmann::detail::json_base_class<void>

Types

Name

Description

allocator_type

the allocator type

array_t

a type for an array

binary_t

a type for a packed binary type

bjdata_version_t

how to encode BJData

boolean_t

a type for a boolean

cbor_tag_handler_t

how to treat CBOR tags

const_iterator

a const iterator for a basic_json container

const_pointer

the type of an element const pointer

const_reference

the type of an element const reference

const_reverse_iterator

a const reverse iterator for a basic_json container

difference_type

a type to represent differences between iterators

error_handler_t

how to treat decoding errors

exception

Classes to implement user‐defined exceptions. @{

initializer_list_t

helper type for initializer lists of basic_json values

input_format_t

invalid_iterator

iterator

an iterator for a basic_json container

JSON Pointer, see nlohmann::json_pointer

json_sax_t

SAX interface type, see nlohmann::json_sax

json_serializer

number_float_t

a type for a number (floating‐point)

number_integer_t

a type for a number (integer)

number_unsigned_t

a type for a number (unsigned)

object_comparator_t

object key comparator type

a type for an object

parser event types

per‐element parser callback type

pointer

the type of an element pointer

reference

the type of an element reference

reverse_iterator

a reverse iterator for a basic_json container

size_type

a type to represent container sizes

a type for a string

the type of elements in a basic_json container

Member Functions

Name

Description

basic_json [constructor]

Construct from nullptr_t

basic_json [constructor]

Construct from value_t

basic_json [constructor]

Construct from basic_json

basic_json [constructor]

Construct from basic_json

basic_json [constructor]

create a JSON value from an existing one

basic_json [constructor]

////////////////////////////////////

basic_json [constructor]

create a JSON value from compatible types

basic_json [constructor]

Constructor

basic_json [constructor]

construct a JSON container given an iterator range

basic_json [constructor]

~basic_json [destructor]

Destructor

operator=

Assignment operator

access specified object element with bounds checking

access specified object element with bounds checking

check the existence of an element in a JSON object

count

returns the number of occurrences of a key in a JSON object

add an object to an object if key does not exist

emplace_back

add an object to an array

empty

end

remove element given an iterator

remove element from a JSON object given a key

remove elements given an iterator range

find an element in a JSON object

find an element in a JSON object

flatten

front

get a pointer value (explicit)

get a (pointer) value (explicit)

get_binary

get a pointer value (implicit)

get a pointer value (implicit)

get a reference value (implicit)

get a reference value (implicit)

get a value (explicit)

insert_iterator

Helper for insertion of an iterator

Addition assignment operator

Addition assignment operator

Addition assignment operator

Addition assignment operator

Subscript operator

Subscript operator

Subscript operator

Subscript operator

Subscript operator

Subscript operator

Subscript operator

Subscript operator

access specified object element

access specified object element

Subscript operator

Subscript operator

access specified object element via JSON Pointer with default value

access specified object element with default value

access specified object element via JSON Pointer with default value

access specified object element with default value

access specified object element with default value

access specified object element via JSON Pointer with default value

operator ValueType

get a value (implicit)

operator value_t

Conversion to value_t

comparison: equal

Equality operator

Inequality operator

comparison: 3‐way

Three‐way comparison operator

Static Member Functions

Name

Description

check if the input is valid JSON

check if the input is valid JSON

create a JSON value from an input in BJData format

from_bjdata

create a JSON value from an input in BJData format

create a JSON value from an input in BSON format

create a JSON value from an input in BSON format

create a JSON value from an input in CBOR format

create a JSON value from an input in CBOR format

create a JSON value from an input in MessagePack format

create a JSON value from an input in MessagePack format

create a JSON value from an input in UBJSON format

create a JSON value from an input in UBJSON format

deserialize from a compatible input

parse

deserialize from a pair of character iterators

generate SAX events

generate SAX events

generate SAX events

Friends

Name

Description

deserialize from stream

deserialize from stream

serialize to stream

default_object_comparator_t

serialize to stream

nlohmann::swap

exchanges the values

nlohmann::detail::exception

general exception of the basic_json class

nlohmann::detail::serializer

nlohmann::json_pointer

JSON Pointer defines a string syntax for identifying a specific value within a JSON document

the allocator type

Synopsis

Declared in <nlohmann/json.hpp>

using allocator_type = allocator<basic_json>;

a type for an array

Synopsis

Declared in <nlohmann/json.hpp>

using array_t = vector<basic_json, allocator<basic_json>>;

a type for a packed binary type

Synopsis

Declared in <nlohmann/json.hpp>

using binary_t = nlohmann::byte_container_with_subtype<vector<unsigned char>>;

how to encode BJData

Synopsis

Declared in <nlohmann/json.hpp>

using bjdata_version_t = detail::bjdata_version_t;

a type for a boolean

Synopsis

Declared in <nlohmann/json.hpp>

using boolean_t = bool;

how to treat CBOR tags

Synopsis

Declared in <nlohmann/json.hpp>

using cbor_tag_handler_t = detail::cbor_tag_handler_t;

a const iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using const_iterator = iter_impl<basic_json const>;

the type of an element const pointer

Synopsis

Declared in <nlohmann/json.hpp>

using const_pointer = std::allocator_traits<allocator_type>::const_pointer;

the type of an element const reference

Synopsis

Declared in <nlohmann/json.hpp>

using const_reference = value_type const&;

a const reverse iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using const_reverse_iterator = json_reverse_iterator<basic_json::const_iterator>;

Synopsis

Declared in <nlohmann/json.hpp>

using default_object_comparator_t = std::less;

a type to represent differences between iterators

Synopsis

Declared in <nlohmann/json.hpp>

using difference_type = std::ptrdiff_t;

how to treat decoding errors

Synopsis

Declared in <nlohmann/json.hpp>

using error_handler_t = detail::error_handler_t;

Classes to implement user‐defined exceptions. @{

Synopsis

Declared in <nlohmann/json.hpp>

using exception = detail::exception;

helper type for initializer lists of basic_json values

Synopsis

Declared in <nlohmann/json.hpp>

using initializer_list_t = std::initializer_list<detail::json_ref<basic_json>>;

Synopsis

Declared in <nlohmann/json.hpp>

using input_format_t = detail::input_format_t;

Synopsis

Declared in <nlohmann/json.hpp>

using invalid_iterator = detail::invalid_iterator;

an iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using iterator = iter_impl<basic_json>;

JSON Pointer, see nlohmann::json_pointer

Synopsis

Declared in <nlohmann/json.hpp>

using json_pointer = nlohmann::json_pointer<basic_string<char>>;

SAX interface type, see nlohmann::json_sax

Synopsis

Declared in <nlohmann/json.hpp>

using json_sax_t = json_sax<basic_json>;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename T,
    typename SFINAE>
using json_serializer = adl_serializer<T, SFINAE>;

a type for a number (floating‐point)

Synopsis

Declared in <nlohmann/json.hpp>

using number_float_t = double;

a type for a number (integer)

Synopsis

Declared in <nlohmann/json.hpp>

using number_integer_t = long long;

a type for a number (unsigned)

Synopsis

Declared in <nlohmann/json.hpp>

using number_unsigned_t = unsigned long long;

object key comparator type

Synopsis

Declared in <nlohmann/json.hpp>

using object_comparator_t = detail::actual_object_comparator_t<basic_json>;

a type for an object

Synopsis

Declared in <nlohmann/json.hpp>

using object_t = map<basic_string<char>, basic_json, default_object_comparator_t, allocator<std::pair<basic_string<char> const, basic_json>>>;

Synopsis

Declared in <nlohmann/json.hpp>

using other_error = detail::other_error;

Synopsis

Declared in <nlohmann/json.hpp>

using out_of_range = detail::out_of_range;

Synopsis

Declared in <nlohmann/json.hpp>

using parse_error = detail::parse_error;

parser event types

Synopsis

Declared in <nlohmann/json.hpp>

using parse_event_t = detail::parse_event_t;

per‐element parser callback type

Synopsis

Declared in <nlohmann/json.hpp>

using parser_callback_t = detail::parser_callback_t<basic_json>;

the type of an element pointer

Synopsis

Declared in <nlohmann/json.hpp>

using pointer = std::allocator_traits<allocator_type>::pointer;

the type of an element reference

Synopsis

Declared in <nlohmann/json.hpp>

using reference = value_type&;

a reverse iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using reverse_iterator = json_reverse_iterator<basic_json::iterator>;

a type to represent container sizes

Synopsis

Declared in <nlohmann/json.hpp>

using size_type = std::size_t;

a type for a string

Synopsis

Declared in <nlohmann/json.hpp>

using string_t = basic_string<char>;

Synopsis

Declared in <nlohmann/json.hpp>

using type_error = detail::type_error;

Synopsis

Declared in <nlohmann/json.hpp>

using value_t = detail::value_t;

the type of elements in a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using value_type = basic_json;

Construct from nullptr_t

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(std::nullptr_t value = nullptr) noexcept;

Parameters

Name

Description

value

The object to construct from

Construct from value_t

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(value_t const v);

Parameters

Name

Description

The object to construct from

Construct from basic_json

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(basic_json const& other);

Parameters

Name

Description

other

The object to copy construct from

Construct from basic_json

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(basic_json&& other) noexcept;

Parameters

Name

Description

other

The object to move construct from

create a JSON value from an existing one

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value&& !std::is_same<basic_json, BasicJsonType>::value
basic_json(BasicJsonType const& val);

Parameters

Name

Description

val

The object to copy construct from

////////////////////////////////////

Synopsis

Declared in <nlohmann/json.hpp>

template<typename JsonRef>
requires detail::conjunction<detail::is_json_ref<JsonRef>,
                                 std::is_same<typename JsonRef::value_type, basic_json>>::value
basic_json(JsonRef const& ref);

Parameters

Name

Description

ref

The object to copy construct from

create a JSON value from compatible types

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename CompatibleType,
    typename U = detail::uncvref_t<CompatibleType>>
requires !detail::is_basic_json<U>::value && detail::is_compatible_type<basic_json_t, U>::value
basic_json(CompatibleType&& val) noexcept(noexcept(JSONSerializer<U, void>::to_json(std::declval<basic_json_t &>(), std::forward<CompatibleType>(val))));

Parameters

Name

Description

val

The object to move construct from

Constructor

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(
    size_type cnt,
    basic_json const& val);

Parameters

Name

Description

cnt

The object to construct from

val

a class to store JSON values

construct a JSON container given an iterator range

Synopsis

Declared in <nlohmann/json.hpp>

template<class InputIT>
requires std::is_same<InputIT, typename basic_json_t::iterator>::value ||
                   std::is_same<InputIT, typename basic_json_t::const_iterator>::value
basic_json(
    InputIT first,
    InputIT last);

Parameters

Name

Description

first

The object to construct from

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(
    initializer_list_t init,
    bool type_deduction = true,
    value_t manual_type = value_t::array);

Destructor

Synopsis

Declared in <nlohmann/json.hpp>

~basic_json() noexcept;

Assignment operator

Synopsis

Declared in <nlohmann/json.hpp>

basic_json&
operator=(basic_json other) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value && std::is_nothrow_move_assignable<json_base_class_t>::value);

Return Value

a class to store JSON values

Parameters

Name

Description

other

The object to assign from

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(size_type idx);

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(size_type idx) const;

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(json_pointer const& ptr);

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(json_pointer const& ptr) const;

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(object_t::key_type const& key);

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(object_t::key_type const& key) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
reference
at(nlohmann::json_pointer<BasicJsonType> const& ptr);

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
const_reference
at(nlohmann::json_pointer<BasicJsonType> const& ptr) const;

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
reference
at(KeyType&& key);

Return Value

the type of an element reference

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_reference
at(KeyType&& key) const;

Return Value

the type of an element const reference

Synopsis

Declared in <nlohmann/json.hpp>

reference
back();

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
back() const;

Synopsis

Declared in <nlohmann/json.hpp>

iterator
begin() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
begin() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
cbegin() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
cend() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

void
clear() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

bool
contains(json_pointer const& ptr) const;

Synopsis

Declared in <nlohmann/json.hpp>

bool
contains(object_t::key_type const& key) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
bool
contains(nlohmann::json_pointer<BasicJsonType> const& ptr) const;

check the existence of an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
bool
contains(KeyType&& key) const;

Synopsis

Declared in <nlohmann/json.hpp>

size_type
count(object_t::key_type const& key) const;

returns the number of occurrences of a key in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
size_type
count(KeyType&& key) const;

Return Value

a type to represent container sizes

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
crbegin() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
crend() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

string_t
dump(
    int const indent = ‐1,
    char const indent_char = ' ',
    bool const ensure_ascii = false,
    error_handler_t const error_handler = error_handler_t::strict) const;

add an object to an object if key does not exist

Synopsis

Declared in <nlohmann/json.hpp>

template<class... Args>
std::pair<iterator, bool>
emplace(Args...&&... args);

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

template<class... Args>
reference
emplace_back(Args...&&... args);

Return Value

the type of an element reference

Synopsis

Declared in <nlohmann/json.hpp>

bool
empty() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

iterator
end() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
end() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

void
erase(size_type const idx);

Synopsis

Declared in <nlohmann/json.hpp>

size_type
erase(object_t::key_type const& key);

remove element given an iterator

Synopsis

Declared in <nlohmann/json.hpp>

template<class IteratorType>
requires std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value
IteratorType
erase(IteratorType pos);

remove element from a JSON object given a key

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
size_type
erase(KeyType&& key);

Return Value

a type to represent container sizes

remove elements given an iterator range

Synopsis

Declared in <nlohmann/json.hpp>

template<class IteratorType>
requires std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value
IteratorType
erase(
    IteratorType first,
    IteratorType last);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
find(object_t::key_type const& key);

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
find(object_t::key_type const& key) const;

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_iterator
find(KeyType&& key) const;

Return Value

a const iterator for a basic_json container

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
iterator
find(KeyType&& key);

Return Value

an iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
flatten() const;

Synopsis

Declared in <nlohmann/json.hpp>

reference
front();

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
front() const;

get a pointer value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value
decltype(std::declval<basic_json_t&>().template get_ptr<PointerType>())
get() noexcept;

Description

Explicit pointer access to the internally stored JSON value. No copies are made.

Warning

The pointer becomes invalid if the underlying JSON object changes.

Constant.

{The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a nullptr is returned if the value and the requested pointer type does not match.,get_PointerType}

Return Value

pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Template Parameters

Name

Description

PointerType

pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t.

get a (pointer) value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename ValueTypeCV,
    typename ValueType = detail::uncvref_t<ValueTypeCV>>
constexpr
decltype(std::declval<const basic_json_t&>().template get_impl<ValueType>(detail::priority_tag<4> {}))
get() const noexcept(noexcept(std::declval<const basic_json_t &>().template get_impl<ValueType>(detail::priority_tag<4>{})));

Description

Performs explicit type conversion between the JSON value and a compatible value if required.

‐ If the requested type is a pointer to the internally stored JSON value that pointer is returned. No copies are made.

‐ If the requested type is the current basic_json, or a different basic_json convertible from the current basic_json.

‐ Otherwise the value is converted by calling the json_serializer<ValueType> from_json() method.

Exceptions

Name

Thrown on

what

json_serializer<ValueType> from_json() method throws if conversion is required

Return Value

copy of the JSON value, converted to

Template Parameters

Name

Description

ValueTypeCV

the provided value type

ValueType

the returned value type

ValueType

if necessary

Synopsis

Declared in <nlohmann/json.hpp>

binary_t&
get_binary();

Synopsis

Declared in <nlohmann/json.hpp>

binary_t const&
get_binary() const;

get a pointer value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value&&
                   std::is_const<typename std::remove_pointer<PointerType>::type>::value
constexpr
decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
get_ptr() const noexcept;

get a pointer value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value
decltype(std::declval<basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
get_ptr() noexcept;

get a reference value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ReferenceType>
requires std::is_reference<ReferenceType>::value
ReferenceType
get_ref();

get a reference value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ReferenceType>
requires std::is_reference<ReferenceType>::value&&
                   std::is_const<typename std::remove_reference<ReferenceType>::type>::value
ReferenceType
get_ref() const;

get a value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires !detail::is_basic_json<ValueType>::value&&
                   detail::has_from_json<basic_json_t, ValueType>::value
ValueType&
get_to(ValueType& v) const noexcept(noexcept(JSONSerializer<ValueType, void>::from_json(std::declval<const basic_json_t &>(), v)));

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires detail::is_basic_json<ValueType>::value
ValueType&
get_to(ValueType& v) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename T,
    std::size_t N,
    typename Array = T(&)[]>
requires detail::has_from_json<basic_json_t, Array>::value
Array
get_to(T(& v)[]) const noexcept(noexcept(JSONSerializer<Array, void>::from_json(std::declval<const basic_json_t &>(), v)));

Synopsis

Declared in <nlohmann/json.hpp>

void
insert(
    const_iterator first,
    const_iterator last);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    initializer_list_t ilist);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    basic_json const& val);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    basic_json&& val);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    const_iterator first,
    const_iterator last);

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    size_type cnt,
    basic_json const& val);

Helper for insertion of an iterator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename... Args>
iterator
insert_iterator(
    const_iterator pos,
    Args...&&... args);

Description

Note	: This uses std::distance to support GCC 4.8, see https://github.com/nlohmann/json/pull/1257

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_array() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_binary() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_boolean() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_discarded() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_null() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_float() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_integer() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_unsigned() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_object() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_primitive() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_string() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_structured() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

iteration_proxy<iterator>
items() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

iteration_proxy<const_iterator>
items() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

size_type
max_size() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

void
merge_patch(basic_json const& apply_patch);

Addition assignment operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(initializer_list_t init);

Return Value

the type of an element reference

Parameters

Name

Description

init

The right operand

Addition assignment operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(object_t::value_type const& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

Addition assignment operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(basic_json const& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

Addition assignment operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(basic_json&& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](object_t::key_type key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](size_type idx);

Return Value

the type of an element reference

Parameters

Name

Description

idx

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](size_type idx) const;

Return Value

the type of an element const reference

Parameters

Name

Description

idx

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](json_pointer const& ptr);

Return Value

the type of an element reference

Parameters

Name

Description

ptr

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](json_pointer const& ptr) const;

Return Value

the type of an element const reference

Parameters

Name

Description

ptr

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](object_t::key_type const& key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
const_reference
operator[](nlohmann::json_pointer<BasicJsonType> const& ptr) const;

Return Value

the type of an element const reference

Parameters

Name

Description

ptr

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
reference
operator[](nlohmann::json_pointer<BasicJsonType> const& ptr);

Return Value

the type of an element reference

Parameters

Name

Description

ptr

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
reference
operator[](KeyType&& key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_reference
operator[](KeyType&& key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
reference
operator[](T* key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
const_reference
operator[](T* key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
patch(basic_json const& json_patch) const;

Synopsis

Declared in <nlohmann/json.hpp>

void
patch_inplace(basic_json const& json_patch);

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(initializer_list_t init);

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(object_t::value_type const& val);

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(basic_json const& val);

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(basic_json&& val);

Synopsis

Declared in <nlohmann/json.hpp>

reverse_iterator
rbegin() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
rbegin() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

reverse_iterator
rend() noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
rend() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

size_type
size() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(reference other) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(array_t& other);

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(binary_t& other);

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(binary_t::container_type& other);

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(object_t& other);

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(string_t& other);

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
value_t
type() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

[[__returns_nonnull__]]
char const*
type_name() const noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
unflatten() const;

Synopsis

Declared in <nlohmann/json.hpp>

void
update(
    const_reference j,
    bool merge_objects = false);

Synopsis

Declared in <nlohmann/json.hpp>

void
update(
    const_iterator first,
    const_iterator last,
    bool merge_objects = false);

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<class ValueType>
requires detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    json_pointer const& ptr,
    ValueType const& default_value) const;

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<class ValueType>
requires !detail::is_transparent<object_comparator_t>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    object_t::key_type const& key,
    ValueType const& default_value) const;

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    json_pointer const& ptr,
    ValueType&& default_value) const;

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class ReturnType = value_return_type<ValueType>::type>
requires !detail::is_transparent<object_comparator_t>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    object_t::key_type const& key,
    ValueType&& default_value) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
[[__deprecated__]]
ValueType
value(
    nlohmann::json_pointer<BasicJsonType> const& ptr,
    ValueType const& default_value) const;

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class KeyType>
requires detail::is_transparent<object_comparator_t>::value
                   && !detail::is_json_pointer<KeyType>::value
                   && is_comparable_with_object_key<KeyType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    KeyType&& key,
    ValueType const& default_value) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class BasicJsonType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
[[__deprecated__]]
ReturnType
value(
    nlohmann::json_pointer<BasicJsonType> const& ptr,
    ValueType&& default_value) const;

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class KeyType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_transparent<object_comparator_t>::value
                   && !detail::is_json_pointer<KeyType>::value
                   && is_comparable_with_object_key<KeyType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    KeyType&& key,
    ValueType&& default_value) const;

get a value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires detail::conjunction <
                       detail::negation<std::is_pointer<ValueType>>,
                       detail::negation<std::is_same<ValueType, std::nullptr_t>>,
                       detail::negation<std::is_same<ValueType, detail::json_ref<basic_json>>>,
                                        detail::negation<std::is_same<ValueType, typename string_t::value_type>>,
                                        detail::negation<detail::is_basic_json<ValueType>>,
                                        detail::negation<std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>>,
#if defined(JSON_HAS_CPP_17) && (defined(__GNUC__) || (defined(_MSC_VER) && _MSC_VER >= 1910 && _MSC_VER <= 1914))
                                                detail::negation<std::is_same<ValueType, std::string_view>>,
#endif
#if defined(JSON_HAS_CPP_17) && JSON_HAS_STATIC_RTTI
                                                detail::negation<std::is_same<ValueType, std::any>>,
#endif
                                                detail::is_detected_lazy<detail::get_template_function, const basic_json_t&, ValueType>
                                                >::value
operator ValueType() const;

Description

Implicit type conversion between the JSON value and a compatible value. The call is realized by calling get() const.

Linear in the size of the JSON value.

{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating‐point numbers can be converted to integers, (2) A JSON array can be converted to a standard std::vector<short>, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string, json>.,operator_ValueType}

Exceptions

Name

Thrown on

type_error.302

in case passed type ValueType is incompatible to the JSON value type (e.g., the JSON value is of type boolean, but a string is requested); see example below

Return Value

copy of the JSON value, converted to type ValueType

Template Parameters

Name

Description

ValueType

non‐pointer type compatible to the JSON value, for instance int for JSON integer numbers, bool for JSON booleans, or std::vector types for JSON arrays. The character type of string_t as well as an initializer list of this type is excluded to avoid ambiguities as these types implicitly convert to std::string.

Conversion to value_t

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
operator value_t() const noexcept;

Return Value

The object converted to value_t

comparison: equal

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ScalarType>
requires std::is_scalar_v<ScalarType>
bool
operator==(ScalarType rhs) const noexcept;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Equality operator

Synopsis

Declared in <nlohmann/json.hpp>

bool
operator==(const_reference rhs) const noexcept;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Inequality operator

Synopsis

Declared in <nlohmann/json.hpp>

bool
operator!=(const_reference rhs) const noexcept;

Return Value

true if the objects are not equal, false otherwise

Parameters

Name

Description

rhs

The right operand

comparison: 3‐way

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ScalarType>
requires std::is_scalar_v<ScalarType>
std::partial_ordering
operator<=>(ScalarType rhs) const noexcept;

Return Value

The relative order of the objects

Parameters

Name

Description

rhs

The right operand

Three‐way comparison operator

Synopsis

Declared in <nlohmann/json.hpp>

std::partial_ordering
operator<=>(const_reference rhs) const noexcept;

Return Value

The relative order of the objects

Parameters

Name

Description

rhs

The right operand

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
bool
accept(
    detail::span_input_adapter&& i,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

check if the input is valid JSON

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
static
bool
accept(
    InputType&& i,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

check if the input is valid JSON

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
static
bool
accept(
    IteratorType first,
    IteratorType last,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
array(initializer_list_t init = {});

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(binary_t::container_type const& init);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(binary_t::container_type&& init);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(
    binary_t::container_type const& init,
    binary_t::subtype_type subtype);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(
    binary_t::container_type&& init,
    binary_t::subtype_type subtype);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
diff(
    basic_json const& source,
    basic_json const& target,
    string_t const& path = "");

create a JSON value from an input in BJData format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_bjdata(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in BJData format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_bjdata(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_bson(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in BSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_bson(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in BSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_bson(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_bson(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_cbor(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

create a JSON value from an input in CBOR format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_cbor(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Return Value

a class to store JSON values

Parameters

Name

Description

tag_handler

how to treat CBOR tags

create a JSON value from an input in CBOR format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_cbor(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Return Value

a class to store JSON values

Parameters

Name

Description

tag_handler

how to treat CBOR tags

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_cbor(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_msgpack(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in MessagePack format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_msgpack(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in MessagePack format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_msgpack(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_msgpack(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_ubjson(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in UBJSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_ubjson(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in UBJSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_ubjson(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_ubjson(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

Synopsis

Declared in <nlohmann/json.hpp>

static
allocator_type
get_allocator();

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
static
iteration_proxy<const_iterator>
iterator_wrapper(const_reference ref) noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
static
iteration_proxy<iterator>
iterator_wrapper(reference ref) noexcept;

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
meta();

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
object(initializer_list_t init = {});

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
parse(
    detail::span_input_adapter&& i,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

deserialize from a compatible input

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
parse(
    InputType&& i,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Return Value

a class to store JSON values

Parameters

Name

Description

per‐element parser callback type

deserialize from a pair of character iterators

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
parse(
    IteratorType first,
    IteratorType last,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Return Value

a class to store JSON values

Parameters

Name

Description

per‐element parser callback type

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<typename SAX>
[[__deprecated__, __nonnull__]]
static
bool
sax_parse(
    detail::span_input_adapter&& i,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename InputType,
    typename SAX>
[[__nonnull__]]
static
bool
sax_parse(
    InputType&& i,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class IteratorType,
    class SAX>
[[__nonnull__]]
static
bool
sax_parse(
    IteratorType first,
    IteratorType last,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_bjdata(
    basic_json const& j,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bjdata(
    basic_json const& j,
    detail::output_adapter<uint8_t> o,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bjdata(
    basic_json const& j,
    detail::output_adapter<char> o,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_bson(basic_json const& j);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bson(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bson(
    basic_json const& j,
    detail::output_adapter<char> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_cbor(basic_json const& j);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_cbor(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_cbor(
    basic_json const& j,
    detail::output_adapter<char> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_msgpack(basic_json const& j);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_msgpack(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_msgpack(
    basic_json const& j,
    detail::output_adapter<char> o);

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_ubjson(
    basic_json const& j,
    bool const use_size = false,
    bool const use_type = false);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_ubjson(
    basic_json const& j,
    detail::output_adapter<uint8_t> o,
    bool const use_size = false,
    bool const use_type = false);

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_ubjson(
    basic_json const& j,
    detail::output_adapter<char> o,
    bool const use_size = false,
    bool const use_type = false);

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<
    template<
    typename U,
    typename V,
    typename... Args> typename ObjectType = map,
    template<
    typename U,
    typename... Args> typename ArrayType = vector,
    class StringType = std::string,
    class BooleanType = bool,
    class NumberIntegerType = int64_t,
    class NumberUnsignedType = uint64_t,
    class NumberFloatType = double,
    template<typename U> typename AllocatorType = allocator,
    template<
    typename T,
    typename SFINAE = void> typename JSONSerializer = adl_serializer,
    class BinaryType = std::vector<uint8_t>,
    class CustomBaseClass = void>
class basic_json
    : public nlohmann::detail::json_base_class<CustomBaseClass>

Base Classes

Name

Description

nlohmann::detail::json_base_class<CustomBaseClass>

Types

Name

Description

allocator_type

the allocator type

array_t

a type for an array

binary_t

a type for a packed binary type

bjdata_version_t

how to encode BJData

boolean_t

a type for a boolean

cbor_tag_handler_t

how to treat CBOR tags

const_iterator

a const iterator for a basic_json container

const_pointer

the type of an element const pointer

const_reference

the type of an element const reference

const_reverse_iterator

a const reverse iterator for a basic_json container

difference_type

a type to represent differences between iterators

error_handler_t

how to treat decoding errors

exception

Classes to implement user‐defined exceptions. @{

initializer_list_t

helper type for initializer lists of basic_json values

input_format_t

invalid_iterator

iterator

an iterator for a basic_json container

JSON Pointer, see nlohmann::json_pointer

json_sax_t

SAX interface type, see nlohmann::json_sax

json_serializer

number_float_t

a type for a number (floating‐point)

number_integer_t

a type for a number (integer)

number_unsigned_t

a type for a number (unsigned)

object_comparator_t

object key comparator type

a type for an object

parser event types

per‐element parser callback type

pointer

the type of an element pointer

reference

the type of an element reference

reverse_iterator

a reverse iterator for a basic_json container

size_type

a type to represent container sizes

a type for a string

the type of elements in a basic_json container

Member Functions

Name

Description

basic_json [constructor]

copy constructor

basic_json [constructor]

move constructor

basic_json [constructor]

create a null object

basic_json [constructor]

create an empty value with a given type

basic_json [constructor]

create a JSON value from an existing one

basic_json [constructor]

////////////////////////////////////

basic_json [constructor]

create a JSON value from compatible types

basic_json [constructor]

construct an array with count copies of given value

basic_json [constructor]

construct a JSON container given an iterator range

basic_json [constructor]

create a container (array or object) from an initializer list

~basic_json [destructor]

destructor

operator=

copy assignment

access specified array element with bounds checking

access specified array element with bounds checking

access specified element via JSON Pointer

access specified element via JSON Pointer

access specified object element with bounds checking

access specified object element with bounds checking

access specified object element with bounds checking

access specified object element with bounds checking

back

access the last element

back

access the last element

begin

returns an iterator to the first element

begin

returns an iterator to the first element

cbegin

returns a const iterator to the first element

cend

returns an iterator to one past the last element

clear

clears the contents

contains

check the existence of an element in a JSON object given a JSON pointer

contains

check the existence of an element in a JSON object

contains

check the existence of an element in a JSON object

count

returns the number of occurrences of a key in a JSON object

count

returns the number of occurrences of a key in a JSON object

crbegin

returns a const reverse iterator to the last element

crend

returns a const reverse iterator to one before the first

dump

serialization

emplace

add an object to an object if key does not exist

emplace_back

add an object to an array

empty

checks whether the container is empty.

end

returns an iterator to one past the last element

end

returns an iterator to one past the last element

remove element from a JSON array given an index

remove element from a JSON object given a key

remove element given an iterator

remove element from a JSON object given a key

remove elements given an iterator range

find an element in a JSON object

find an element in a JSON object

find an element in a JSON object

find an element in a JSON object

flatten

return flattened JSON value

front

access the first element

front

access the first element

get a pointer value (explicit)

get a (pointer) value (explicit)

get_binary

get a binary value

get_binary

get a binary value

get a pointer value (implicit)

get a pointer value (implicit)

get a reference value (implicit)

get a reference value (implicit)

get a value (explicit)

inserts range of elements into object

inserts elements from initializer list into array

inserts element into array

inserts element into array

inserts range of elements into array

inserts copies of element into array

insert_iterator

Helper for insertion of an iterator

is_array

return whether value is an array

is_binary

return whether value is a binary array

is_boolean

return whether value is a boolean

is_discarded

return whether value is discarded

is_null

return whether value is null

is_number

return whether value is a number

is_number_float

return whether value is a floating‐point number

is_number_integer

return whether value is an integer number

is_number_unsigned

return whether value is an unsigned integer number

is_object

return whether value is an object

is_primitive

return whether type is primitive

is_string

return whether value is a string

is_structured

return whether type is structured

items

helper to access iterator member functions in range‐based for

items

helper to access iterator member functions in range‐based for

max_size

returns the maximum possible number of elements

merge_patch

applies a JSON Merge Patch

add an object to an object

add an object to an array

add an object to an object

add an object to an array

access specified object element

access specified array element

access specified array element

access specified element via JSON Pointer

access specified element via JSON Pointer

access specified object element

Subscript operator

Subscript operator

access specified object element

access specified object element

Subscript operator

Subscript operator

patch

applies a JSON patch to a copy of the current object

patch_inplace

applies a JSON patch in‐place without copying the object

add an object to an object

add an object to an array

add an object to an object

add an object to an array

rbegin

returns an iterator to the reverse‐beginning

rbegin

returns an iterator to the reverse‐beginning

rend

returns an iterator to the reverse‐end

rend

returns an iterator to the reverse‐end

size

returns the number of elements

exchanges the values

exchanges the values

exchanges the values

exchanges the values

exchanges the values

exchanges the values

return the type of the JSON value (explicit)

type_name

return the type as string

unflatten

unflatten a previously flattened JSON value

update

updates a JSON object from another object, overwriting existing keys

update

updates a JSON object from another object, overwriting existing keys

access specified object element via JSON Pointer with default value

access specified object element with default value

access specified object element via JSON Pointer with default value

access specified object element with default value

access specified object element with default value

access specified object element via JSON Pointer with default value

operator ValueType

get a value (implicit)

operator value_t

return the type of the JSON value (implicit)

operator==

comparison: equal

operator==

comparison: equal

operator!=

comparison: not equal

operator<=>

comparison: 3‐way

operator<=>

comparison: 3‐way

Static Member Functions

Name

Description

check if the input is valid JSON

check if the input is valid JSON

array

explicitly create an array from an initializer list

explicitly create a binary array (without subtype)

explicitly create a binary array

explicitly create a binary array (with subtype)

explicitly create a binary array (with subtype)

diff

creates a diff as a JSON patch

from_bjdata

create a JSON value from an input in BJData format

from_bjdata

create a JSON value from an input in BJData format

create a JSON value from an input in BSON format

create a JSON value from an input in BSON format

create a JSON value from an input in CBOR format

create a JSON value from an input in CBOR format

create a JSON value from an input in MessagePack format

create a JSON value from an input in MessagePack format

create a JSON value from an input in UBJSON format

create a JSON value from an input in UBJSON format

get_allocator

returns the allocator associated with the container

iterator_wrapper

wrapper to access iterator member functions in range‐based for

iterator_wrapper

wrapper to access iterator member functions in range‐based for

meta

returns version information on the library

object

explicitly create an object from an initializer list

parse

deserialize from a compatible input

parse

deserialize from a pair of character iterators

generate SAX events

generate SAX events

generate SAX events

create a BJData serialization of a given JSON value

to_bjdata

create a BJData serialization of a given JSON value

to_bjdata

create a BJData serialization of a given JSON value

to_bson

create a BSON serialization of a given JSON value

to_bson

create a BSON serialization of a given JSON value

to_bson

create a BSON serialization of a given JSON value

to_cbor

create a CBOR serialization of a given JSON value

to_cbor

create a CBOR serialization of a given JSON value

to_cbor

create a CBOR serialization of a given JSON value

to_msgpack

create a MessagePack serialization of a given JSON value

to_msgpack

create a MessagePack serialization of a given JSON value

to_msgpack

create a MessagePack serialization of a given JSON value

to_ubjson

create a UBJSON serialization of a given JSON value

to_ubjson

create a UBJSON serialization of a given JSON value

to_ubjson

create a UBJSON serialization of a given JSON value

Friends

Name

Description

deserialize from stream

deserialize from stream

serialize to stream

serialize to stream

nlohmann::swap

exchanges the values

nlohmann::detail::exception

general exception of the basic_json class

nlohmann::detail::serializer

nlohmann::json_pointer

Non-Member Functions

Name

Description

operator<<

deserialize from stream

operator>>

serialize to stream

to_string

user‐defined to_string function for JSON values

Description

a class to store JSON values

@invariant The member variables @a m_value and @a m_type have the following
relationship:
- If `m_type == value_t::object`, then `m_value.object != nullptr`.
- If `m_type == value_t::array`, then `m_value.array != nullptr`.
- If `m_type == value_t::string`, then `m_value.string != nullptr`.
The invariants are checked by member function assert_invariant().

@note ObjectType trick from https://stackoverflow.com/a/9860911

the allocator type

Synopsis

Declared in <nlohmann/json.hpp>

using allocator_type = AllocatorType<basic_json>;

a type for an array

Synopsis

Declared in <nlohmann/json.hpp>

using array_t = ArrayType<basic_json, AllocatorType<basic_json>>;

a type for a packed binary type

Synopsis

Declared in <nlohmann/json.hpp>

using binary_t = nlohmann::byte_container_with_subtype<BinaryType>;

how to encode BJData

Synopsis

Declared in <nlohmann/json.hpp>

using bjdata_version_t = detail::bjdata_version_t;

a type for a boolean

Synopsis

Declared in <nlohmann/json.hpp>

using boolean_t = BooleanType;

how to treat CBOR tags

Synopsis

Declared in <nlohmann/json.hpp>

using cbor_tag_handler_t = detail::cbor_tag_handler_t;

a const iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using const_iterator = iter_impl<basic_json const>;

the type of an element const pointer

Synopsis

Declared in <nlohmann/json.hpp>

using const_pointer = std::allocator_traits<allocator_type>::const_pointer;

the type of an element const reference

Synopsis

Declared in <nlohmann/json.hpp>

using const_reference = value_type const&;

a const reverse iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using const_reverse_iterator = json_reverse_iterator<basic_json::const_iterator>;

Synopsis

Declared in <nlohmann/json.hpp>

using default_object_comparator_t = std::less;

a type to represent differences between iterators

Synopsis

Declared in <nlohmann/json.hpp>

using difference_type = std::ptrdiff_t;

how to treat decoding errors

Synopsis

Declared in <nlohmann/json.hpp>

using error_handler_t = detail::error_handler_t;

Classes to implement user‐defined exceptions. @{

Synopsis

Declared in <nlohmann/json.hpp>

using exception = detail::exception;

helper type for initializer lists of basic_json values

Synopsis

Declared in <nlohmann/json.hpp>

using initializer_list_t = std::initializer_list<detail::json_ref<basic_json>>;

Synopsis

Declared in <nlohmann/json.hpp>

using input_format_t = detail::input_format_t;

Synopsis

Declared in <nlohmann/json.hpp>

using invalid_iterator = detail::invalid_iterator;

an iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using iterator = iter_impl<basic_json>;

JSON Pointer, see nlohmann::json_pointer

Synopsis

Declared in <nlohmann/json.hpp>

using json_pointer = nlohmann::json_pointer<StringType>;

SAX interface type, see nlohmann::json_sax

Synopsis

Declared in <nlohmann/json.hpp>

using json_sax_t = json_sax<basic_json>;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename T,
    typename SFINAE>
using json_serializer = JSONSerializer<T, SFINAE>;

a type for a number (floating‐point)

Synopsis

Declared in <nlohmann/json.hpp>

using number_float_t = NumberFloatType;

a type for a number (integer)

Synopsis

Declared in <nlohmann/json.hpp>

using number_integer_t = NumberIntegerType;

a type for a number (unsigned)

Synopsis

Declared in <nlohmann/json.hpp>

using number_unsigned_t = NumberUnsignedType;

object key comparator type

Synopsis

Declared in <nlohmann/json.hpp>

using object_comparator_t = detail::actual_object_comparator_t<basic_json>;

a type for an object

Synopsis

Declared in <nlohmann/json.hpp>

using object_t = ObjectType<StringType, basic_json, default_object_comparator_t, AllocatorType<std::pair<StringType const, basic_json>>>;

Synopsis

Declared in <nlohmann/json.hpp>

using other_error = detail::other_error;

Synopsis

Declared in <nlohmann/json.hpp>

using out_of_range = detail::out_of_range;

Synopsis

Declared in <nlohmann/json.hpp>

using parse_error = detail::parse_error;

parser event types

Synopsis

Declared in <nlohmann/json.hpp>

using parse_event_t = detail::parse_event_t;

per‐element parser callback type

Synopsis

Declared in <nlohmann/json.hpp>

using parser_callback_t = detail::parser_callback_t<basic_json>;

the type of an element pointer

Synopsis

Declared in <nlohmann/json.hpp>

using pointer = std::allocator_traits<allocator_type>::pointer;

the type of an element reference

Synopsis

Declared in <nlohmann/json.hpp>

using reference = value_type&;

a reverse iterator for a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using reverse_iterator = json_reverse_iterator<basic_json::iterator>;

a type to represent container sizes

Synopsis

Declared in <nlohmann/json.hpp>

using size_type = std::size_t;

a type for a string

Synopsis

Declared in <nlohmann/json.hpp>

using string_t = StringType;

Synopsis

Declared in <nlohmann/json.hpp>

using type_error = detail::type_error;

Synopsis

Declared in <nlohmann/json.hpp>

using value_t = detail::value_t;

the type of elements in a basic_json container

Synopsis

Declared in <nlohmann/json.hpp>

using value_type = basic_json;

copy constructor

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(basic_json const& other);

Parameters

Name

Description

other

The object to copy construct from

move constructor

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(basic_json&& other) noexcept;

Parameters

Name

Description

other

The object to move construct from

create a null object

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(std::nullptr_t value = nullptr) noexcept;

Parameters

Name

Description

value

The object to construct from

create an empty value with a given type

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(value_t const v);

Parameters

Name

Description

The object to construct from

create a JSON value from an existing one

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value&& !std::is_same<basic_json, BasicJsonType>::value
basic_json(BasicJsonType const& val);

Parameters

Name

Description

val

The object to copy construct from

////////////////////////////////////

Synopsis

Declared in <nlohmann/json.hpp>

template<typename JsonRef>
requires detail::conjunction<detail::is_json_ref<JsonRef>,
                                 std::is_same<typename JsonRef::value_type, basic_json>>::value
basic_json(JsonRef const& ref);

Parameters

Name

Description

ref

The object to copy construct from

create a JSON value from compatible types

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename CompatibleType,
    typename U = detail::uncvref_t<CompatibleType>>
requires !detail::is_basic_json<U>::value && detail::is_compatible_type<basic_json_t, U>::value
basic_json(CompatibleType&& val) noexcept(noexcept(JSONSerializer<U, void>::to_json(std::declval<basic_json_t &>(), std::forward<CompatibleType>(val))));

Parameters

Name

Description

val

The object to move construct from

construct an array with count copies of given value

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(
    size_type cnt,
    basic_json const& val);

Parameters

Name

Description

cnt

The object to construct from

val

a class to store JSON values

construct a JSON container given an iterator range

Synopsis

Declared in <nlohmann/json.hpp>

template<class InputIT>
requires std::is_same<InputIT, typename basic_json_t::iterator>::value ||
                   std::is_same<InputIT, typename basic_json_t::const_iterator>::value
basic_json(
    InputIT first,
    InputIT last);

Parameters

Name

Description

first

The object to construct from

create a container (array or object) from an initializer list

Synopsis

Declared in <nlohmann/json.hpp>

basic_json(
    initializer_list_t init,
    bool type_deduction = true,
    value_t manual_type = value_t::array);

Parameters

Name

Description

init

The object to construct from

destructor

Synopsis

Declared in <nlohmann/json.hpp>

~basic_json() noexcept;

copy assignment

Synopsis

Declared in <nlohmann/json.hpp>

basic_json&
operator=(basic_json other) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value && std::is_nothrow_move_assignable<json_base_class_t>::value);

Return Value

Reference to the current object

Parameters

Name

Description

other

The object to assign from

access specified array element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(size_type idx);

Return Value

the type of an element reference

Parameters

Name

Description

idx

a type to represent container sizes

access specified array element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(size_type idx) const;

Return Value

the type of an element const reference

Parameters

Name

Description

idx

a type to represent container sizes

access specified element via JSON Pointer

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(json_pointer const& ptr);

Return Value

the type of an element reference

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified element via JSON Pointer

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(json_pointer const& ptr) const;

Return Value

the type of an element const reference

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

reference
at(object_t::key_type const& key);

Return Value

the type of an element reference

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
at(object_t::key_type const& key) const;

Return Value

the type of an element const reference

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
reference
at(nlohmann::json_pointer<BasicJsonType> const& ptr);

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
const_reference
at(nlohmann::json_pointer<BasicJsonType> const& ptr) const;

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_reference
at(KeyType&& key) const;

Return Value

the type of an element const reference

access specified object element with bounds checking

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
reference
at(KeyType&& key);

Return Value

the type of an element reference

access the last element

Synopsis

Declared in <nlohmann/json.hpp>

reference
back();

Return Value

the type of an element reference

access the last element

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
back() const;

Return Value

the type of an element const reference

returns an iterator to the first element

Synopsis

Declared in <nlohmann/json.hpp>

iterator
begin() noexcept;

Return Value

an iterator for a basic_json container

returns an iterator to the first element

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
begin() const noexcept;

Return Value

a const iterator for a basic_json container

returns a const iterator to the first element

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
cbegin() const noexcept;

Return Value

a const iterator for a basic_json container

returns an iterator to one past the last element

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
cend() const noexcept;

Return Value

a const iterator for a basic_json container

clears the contents

Synopsis

Declared in <nlohmann/json.hpp>

void
clear() noexcept;

check the existence of an element in a JSON object given a JSON pointer

Synopsis

Declared in <nlohmann/json.hpp>

bool
contains(json_pointer const& ptr) const;

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

check the existence of an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

bool
contains(object_t::key_type const& key) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
bool
contains(nlohmann::json_pointer<BasicJsonType> const& ptr) const;

check the existence of an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
bool
contains(KeyType&& key) const;

returns the number of occurrences of a key in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

size_type
count(object_t::key_type const& key) const;

Return Value

a type to represent container sizes

returns the number of occurrences of a key in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
size_type
count(KeyType&& key) const;

Return Value

a type to represent container sizes

returns a const reverse iterator to the last element

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
crbegin() const noexcept;

Return Value

a const reverse iterator for a basic_json container

returns a const reverse iterator to one before the first

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
crend() const noexcept;

Return Value

a const reverse iterator for a basic_json container

serialization

Synopsis

Declared in <nlohmann/json.hpp>

string_t
dump(
    int const indent = ‐1,
    char const indent_char = ' ',
    bool const ensure_ascii = false,
    error_handler_t const error_handler = error_handler_t::strict) const;

Return Value

a type for a string

Parameters

Name

Description

error_handler

how to treat decoding errors

add an object to an object if key does not exist

Synopsis

Declared in <nlohmann/json.hpp>

template<class... Args>
std::pair<iterator, bool>
emplace(Args...&&... args);

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

template<class... Args>
reference
emplace_back(Args...&&... args);

Return Value

the type of an element reference

checks whether the container is empty.

Synopsis

Declared in <nlohmann/json.hpp>

bool
empty() const noexcept;

returns an iterator to one past the last element

Synopsis

Declared in <nlohmann/json.hpp>

iterator
end() noexcept;

Return Value

an iterator for a basic_json container

returns an iterator to one past the last element

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
end() const noexcept;

Return Value

a const iterator for a basic_json container

remove element from a JSON array given an index

Synopsis

Declared in <nlohmann/json.hpp>

void
erase(size_type const idx);

Parameters

Name

Description

idx

a type to represent container sizes

remove element from a JSON object given a key

Synopsis

Declared in <nlohmann/json.hpp>

size_type
erase(object_t::key_type const& key);

Return Value

a type to represent container sizes

remove element given an iterator

Synopsis

Declared in <nlohmann/json.hpp>

template<class IteratorType>
requires std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value
IteratorType
erase(IteratorType pos);

remove element from a JSON object given a key

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
size_type
erase(KeyType&& key);

Return Value

a type to represent container sizes

remove elements given an iterator range

Synopsis

Declared in <nlohmann/json.hpp>

template<class IteratorType>
requires std::is_same<IteratorType, typename basic_json_t::iterator>::value ||
                   std::is_same<IteratorType, typename basic_json_t::const_iterator>::value
IteratorType
erase(
    IteratorType first,
    IteratorType last);

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

iterator
find(object_t::key_type const& key);

Return Value

an iterator for a basic_json container

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

const_iterator
find(object_t::key_type const& key) const;

Return Value

a const iterator for a basic_json container

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_iterator
find(KeyType&& key) const;

Return Value

a const iterator for a basic_json container

find an element in a JSON object

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
iterator
find(KeyType&& key);

Return Value

an iterator for a basic_json container

return flattened JSON value

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
flatten() const;

Return Value

a class to store JSON values

access the first element

Synopsis

Declared in <nlohmann/json.hpp>

reference
front();

Return Value

the type of an element reference

access the first element

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
front() const;

Return Value

the type of an element const reference

get a pointer value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value
decltype(std::declval<basic_json_t&>().template get_ptr<PointerType>())
get() noexcept;

Description

Explicit pointer access to the internally stored JSON value. No copies are made.

Warning

The pointer becomes invalid if the underlying JSON object changes.

Constant.

Return Value

pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; nullptr otherwise

Template Parameters

Name

Description

PointerType

pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, number_unsigned_t, or number_float_t.

get a (pointer) value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename ValueTypeCV,
    typename ValueType = detail::uncvref_t<ValueTypeCV>>
constexpr
decltype(std::declval<const basic_json_t&>().template get_impl<ValueType>(detail::priority_tag<4> {}))
get() const noexcept(noexcept(std::declval<const basic_json_t &>().template get_impl<ValueType>(detail::priority_tag<4>{})));

Description

Performs explicit type conversion between the JSON value and a compatible value if required.

‐ If the requested type is a pointer to the internally stored JSON value that pointer is returned. No copies are made.

‐ If the requested type is the current basic_json, or a different basic_json convertible from the current basic_json.

‐ Otherwise the value is converted by calling the json_serializer<ValueType> from_json() method.

Exceptions

Name

Thrown on

what

json_serializer<ValueType> from_json() method throws if conversion is required

Return Value

copy of the JSON value, converted to

Template Parameters

Name

Description

ValueTypeCV

the provided value type

ValueType

the returned value type

ValueType

if necessary

get a binary value

Synopsis

Declared in <nlohmann/json.hpp>

binary_t&
get_binary();

Return Value

a type for a packed binary type

get a binary value

Synopsis

Declared in <nlohmann/json.hpp>

binary_t const&
get_binary() const;

Return Value

a type for a packed binary type

get a pointer value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value&&
                   std::is_const<typename std::remove_pointer<PointerType>::type>::value
constexpr
decltype(std::declval<const basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
get_ptr() const noexcept;

get a pointer value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename PointerType>
requires std::is_pointer<PointerType>::value
decltype(std::declval<basic_json_t&>().get_impl_ptr(std::declval<PointerType>()))
get_ptr() noexcept;

get a reference value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ReferenceType>
requires std::is_reference<ReferenceType>::value
ReferenceType
get_ref();

get a reference value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ReferenceType>
requires std::is_reference<ReferenceType>::value&&
                   std::is_const<typename std::remove_reference<ReferenceType>::type>::value
ReferenceType
get_ref() const;

get a value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires !detail::is_basic_json<ValueType>::value&&
                   detail::has_from_json<basic_json_t, ValueType>::value
ValueType&
get_to(ValueType& v) const noexcept(noexcept(JSONSerializer<ValueType, void>::from_json(std::declval<const basic_json_t &>(), v)));

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires detail::is_basic_json<ValueType>::value
ValueType&
get_to(ValueType& v) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename T,
    std::size_t N,
    typename Array = T(&)[]>
requires detail::has_from_json<basic_json_t, Array>::value
Array
get_to(T(& v)[]) const noexcept(noexcept(JSONSerializer<Array, void>::from_json(std::declval<const basic_json_t &>(), v)));

inserts range of elements into object

Synopsis

Declared in <nlohmann/json.hpp>

void
insert(
    const_iterator first,
    const_iterator last);

Parameters

Name

Description

first

a const iterator for a basic_json container

last

a const iterator for a basic_json container

inserts elements from initializer list into array

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    initializer_list_t ilist);

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

ilist

helper type for initializer lists of basic_json values

inserts element into array

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    basic_json const& val);

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

val

a class to store JSON values

inserts element into array

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    basic_json&& val);

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

val

a class to store JSON values

inserts range of elements into array

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    const_iterator first,
    const_iterator last);

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

first

a const iterator for a basic_json container

last

a const iterator for a basic_json container

inserts copies of element into array

Synopsis

Declared in <nlohmann/json.hpp>

iterator
insert(
    const_iterator pos,
    size_type cnt,
    basic_json const& val);

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

cnt

a type to represent container sizes

val

a class to store JSON values

Helper for insertion of an iterator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename... Args>
iterator
insert_iterator(
    const_iterator pos,
    Args...&&... args);

Description

Note	: This uses std::distance to support GCC 4.8, see https://github.com/nlohmann/json/pull/1257

Return Value

an iterator for a basic_json container

Parameters

Name

Description

pos

a const iterator for a basic_json container

return whether value is an array

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_array() const noexcept;

return whether value is a binary array

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_binary() const noexcept;

return whether value is a boolean

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_boolean() const noexcept;

return whether value is discarded

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_discarded() const noexcept;

return whether value is null

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_null() const noexcept;

return whether value is a number

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number() const noexcept;

return whether value is a floating‐point number

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_float() const noexcept;

return whether value is an integer number

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_integer() const noexcept;

return whether value is an unsigned integer number

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_number_unsigned() const noexcept;

return whether value is an object

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_object() const noexcept;

return whether type is primitive

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_primitive() const noexcept;

return whether value is a string

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_string() const noexcept;

return whether type is structured

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
bool
is_structured() const noexcept;

helper to access iterator member functions in range‐based for

Synopsis

Declared in <nlohmann/json.hpp>

iteration_proxy<iterator>
items() noexcept;

helper to access iterator member functions in range‐based for

Synopsis

Declared in <nlohmann/json.hpp>

iteration_proxy<const_iterator>
items() const noexcept;

returns the maximum possible number of elements

Synopsis

Declared in <nlohmann/json.hpp>

size_type
max_size() const noexcept;

Return Value

a type to represent container sizes

applies a JSON Merge Patch

Synopsis

Declared in <nlohmann/json.hpp>

void
merge_patch(basic_json const& apply_patch);

Parameters

Name

Description

apply_patch

a class to store JSON values

add an object to an object

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(initializer_list_t init);

Return Value

the type of an element reference

Parameters

Name

Description

init

The right operand

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(basic_json const& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

add an object to an object

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(object_t::value_type const& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator+=(basic_json&& val);

Return Value

the type of an element reference

Parameters

Name

Description

val

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](object_t::key_type key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

access specified array element

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](size_type idx);

Return Value

the type of an element reference

Parameters

Name

Description

idx

The right operand

access specified array element

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](size_type idx) const;

Return Value

the type of an element const reference

Parameters

Name

Description

idx

The right operand

access specified element via JSON Pointer

Synopsis

Declared in <nlohmann/json.hpp>

reference
operator[](json_pointer const& ptr);

Return Value

the type of an element reference

Parameters

Name

Description

ptr

The right operand

access specified element via JSON Pointer

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](json_pointer const& ptr) const;

Return Value

the type of an element const reference

Parameters

Name

Description

ptr

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

const_reference
operator[](object_t::key_type const& key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
const_reference
operator[](nlohmann::json_pointer<BasicJsonType> const& ptr) const;

Return Value

the type of an element const reference

Parameters

Name

Description

ptr

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
[[__deprecated__]]
reference
operator[](nlohmann::json_pointer<BasicJsonType> const& ptr);

Return Value

the type of an element reference

Parameters

Name

Description

ptr

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
reference
operator[](KeyType&& key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

access specified object element

Synopsis

Declared in <nlohmann/json.hpp>

template<class KeyType>
requires detail::is_usable_as_basic_json_key_type<basic_json_t, KeyType>::value
const_reference
operator[](KeyType&& key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
reference
operator[](T* key);

Return Value

the type of an element reference

Parameters

Name

Description

key

The right operand

Subscript operator

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
const_reference
operator[](T* key) const;

Return Value

the type of an element const reference

Parameters

Name

Description

key

The right operand

applies a JSON patch to a copy of the current object

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
patch(basic_json const& json_patch) const;

Return Value

a class to store JSON values

Parameters

Name

Description

json_patch

a class to store JSON values

applies a JSON patch in‐place without copying the object

Synopsis

Declared in <nlohmann/json.hpp>

void
patch_inplace(basic_json const& json_patch);

Parameters

Name

Description

json_patch

a class to store JSON values

add an object to an object

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(initializer_list_t init);

Parameters

Name

Description

init

helper type for initializer lists of basic_json values

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(basic_json const& val);

Parameters

Name

Description

val

a class to store JSON values

add an object to an object

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(object_t::value_type const& val);

add an object to an array

Synopsis

Declared in <nlohmann/json.hpp>

void
push_back(basic_json&& val);

Parameters

Name

Description

val

a class to store JSON values

returns an iterator to the reverse‐beginning

Synopsis

Declared in <nlohmann/json.hpp>

reverse_iterator
rbegin() noexcept;

Return Value

a reverse iterator for a basic_json container

returns an iterator to the reverse‐beginning

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
rbegin() const noexcept;

Return Value

a const reverse iterator for a basic_json container

returns an iterator to the reverse‐end

Synopsis

Declared in <nlohmann/json.hpp>

reverse_iterator
rend() noexcept;

Return Value

a reverse iterator for a basic_json container

returns an iterator to the reverse‐end

Synopsis

Declared in <nlohmann/json.hpp>

const_reverse_iterator
rend() const noexcept;

Return Value

a const reverse iterator for a basic_json container

returns the number of elements

Synopsis

Declared in <nlohmann/json.hpp>

size_type
size() const noexcept;

Return Value

a type to represent container sizes

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(reference other) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

Parameters

Name

Description

other

the type of an element reference

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(array_t& other);

Parameters

Name

Description

other

a type for an array

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(binary_t& other);

Parameters

Name

Description

other

a type for a packed binary type

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(binary_t::container_type& other);

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(object_t& other);

Parameters

Name

Description

other

a type for an object

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(string_t& other);

Parameters

Name

Description

other

a type for a string

return the type of the JSON value (explicit)

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
value_t
type() const noexcept;

return the type as string

Synopsis

Declared in <nlohmann/json.hpp>

[[__returns_nonnull__]]
char const*
type_name() const noexcept;

unflatten a previously flattened JSON value

Synopsis

Declared in <nlohmann/json.hpp>

basic_json
unflatten() const;

Return Value

a class to store JSON values

updates a JSON object from another object, overwriting existing keys

Synopsis

Declared in <nlohmann/json.hpp>

void
update(
    const_reference j,
    bool merge_objects = false);

Parameters

Name

Description

the type of an element const reference

updates a JSON object from another object, overwriting existing keys

Synopsis

Declared in <nlohmann/json.hpp>

void
update(
    const_iterator first,
    const_iterator last,
    bool merge_objects = false);

Parameters

Name

Description

first

a const iterator for a basic_json container

last

a const iterator for a basic_json container

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<class ValueType>
requires detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    json_pointer const& ptr,
    ValueType const& default_value) const;

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<class ValueType>
requires !detail::is_transparent<object_comparator_t>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    object_t::key_type const& key,
    ValueType const& default_value) const;

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    json_pointer const& ptr,
    ValueType&& default_value) const;

Parameters

Name

Description

ptr

JSON Pointer, see nlohmann::json_pointer

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class ReturnType = value_return_type<ValueType>::type>
requires !detail::is_transparent<object_comparator_t>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    object_t::key_type const& key,
    ValueType&& default_value) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class BasicJsonType>
requires detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
[[__deprecated__]]
ValueType
value(
    nlohmann::json_pointer<BasicJsonType> const& ptr,
    ValueType const& default_value) const;

access specified object element with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class KeyType>
requires detail::is_transparent<object_comparator_t>::value
                   && !detail::is_json_pointer<KeyType>::value
                   && is_comparable_with_object_key<KeyType>::value
                   && detail::is_getable<basic_json_t, ValueType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ValueType
value(
    KeyType&& key,
    ValueType const& default_value) const;

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class BasicJsonType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_basic_json<BasicJsonType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
[[__deprecated__]]
ReturnType
value(
    nlohmann::json_pointer<BasicJsonType> const& ptr,
    ValueType&& default_value) const;

access specified object element via JSON Pointer with default value

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class ValueType,
    class KeyType,
    class ReturnType = value_return_type<ValueType>::type>
requires detail::is_transparent<object_comparator_t>::value
                   && !detail::is_json_pointer<KeyType>::value
                   && is_comparable_with_object_key<KeyType>::value
                   && detail::is_getable<basic_json_t, ReturnType>::value
                   && !std::is_same<value_t, detail::uncvref_t<ValueType>>::value
ReturnType
value(
    KeyType&& key,
    ValueType&& default_value) const;

get a value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ValueType>
requires detail::conjunction <
                       detail::negation<std::is_pointer<ValueType>>,
                       detail::negation<std::is_same<ValueType, std::nullptr_t>>,
                       detail::negation<std::is_same<ValueType, detail::json_ref<basic_json>>>,
                                        detail::negation<std::is_same<ValueType, typename string_t::value_type>>,
                                        detail::negation<detail::is_basic_json<ValueType>>,
                                        detail::negation<std::is_same<ValueType, std::initializer_list<typename string_t::value_type>>>,
#if defined(JSON_HAS_CPP_17) && (defined(__GNUC__) || (defined(_MSC_VER) && _MSC_VER >= 1910 && _MSC_VER <= 1914))
                                                detail::negation<std::is_same<ValueType, std::string_view>>,
#endif
#if defined(JSON_HAS_CPP_17) && JSON_HAS_STATIC_RTTI
                                                detail::negation<std::is_same<ValueType, std::any>>,
#endif
                                                detail::is_detected_lazy<detail::get_template_function, const basic_json_t&, ValueType>
                                                >::value
operator ValueType() const;

Description

Implicit type conversion between the JSON value and a compatible value. The call is realized by calling get() const.

Linear in the size of the JSON value.

Exceptions

Name

Thrown on

type_error.302

in case passed type ValueType is incompatible to the JSON value type (e.g., the JSON value is of type boolean, but a string is requested); see example below

Return Value

copy of the JSON value, converted to type ValueType

Template Parameters

Name

Description

ValueType

return the type of the JSON value (implicit)

Synopsis

Declared in <nlohmann/json.hpp>

constexpr
operator value_t() const noexcept;

Return Value

The object converted to value_t

comparison: equal

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ScalarType>
requires std::is_scalar_v<ScalarType>
bool
operator==(ScalarType rhs) const noexcept;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

comparison: equal

Synopsis

Declared in <nlohmann/json.hpp>

bool
operator==(const_reference rhs) const noexcept;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

comparison: not equal

Synopsis

Declared in <nlohmann/json.hpp>

bool
operator!=(const_reference rhs) const noexcept;

Return Value

true if the objects are not equal, false otherwise

Parameters

Name

Description

rhs

The right operand

comparison: 3‐way

Synopsis

Declared in <nlohmann/json.hpp>

template<typename ScalarType>
requires std::is_scalar_v<ScalarType>
std::partial_ordering
operator<=>(ScalarType rhs) const noexcept;

Return Value

The relative order of the objects

Parameters

Name

Description

rhs

The right operand

comparison: 3‐way

Synopsis

Declared in <nlohmann/json.hpp>

std::partial_ordering
operator<=>(const_reference rhs) const noexcept;

Return Value

The relative order of the objects

Parameters

Name

Description

rhs

The right operand

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
bool
accept(
    detail::span_input_adapter&& i,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

check if the input is valid JSON

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
static
bool
accept(
    InputType&& i,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

check if the input is valid JSON

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
static
bool
accept(
    IteratorType first,
    IteratorType last,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

explicitly create an array from an initializer list

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
array(initializer_list_t init = {});

Return Value

a class to store JSON values

Parameters

Name

Description

init

helper type for initializer lists of basic_json values

explicitly create a binary array (without subtype)

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(binary_t::container_type const& init);

Return Value

a class to store JSON values

explicitly create a binary array

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(binary_t::container_type&& init);

Return Value

a class to store JSON values

explicitly create a binary array (with subtype)

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(
    binary_t::container_type const& init,
    binary_t::subtype_type subtype);

Return Value

a class to store JSON values

explicitly create a binary array (with subtype)

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
binary(
    binary_t::container_type&& init,
    binary_t::subtype_type subtype);

Return Value

a class to store JSON values

creates a diff as a JSON patch

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
diff(
    basic_json const& source,
    basic_json const& target,
    string_t const& path = "");

Return Value

a class to store JSON values

Parameters

Name

Description

source

a class to store JSON values

target

a class to store JSON values

path

a type for a string

create a JSON value from an input in BJData format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_bjdata(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in BJData format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_bjdata(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_bson(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in BSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_bson(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in BSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_bson(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_bson(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_cbor(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

create a JSON value from an input in CBOR format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_cbor(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Return Value

a class to store JSON values

Parameters

Name

Description

tag_handler

how to treat CBOR tags

create a JSON value from an input in CBOR format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_cbor(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Return Value

a class to store JSON values

Parameters

Name

Description

tag_handler

how to treat CBOR tags

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_cbor(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true,
    cbor_tag_handler_t const tag_handler = cbor_tag_handler_t::error);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_msgpack(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in MessagePack format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_msgpack(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in MessagePack format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_msgpack(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_msgpack(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_ubjson(
    detail::span_input_adapter&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

create a JSON value from an input in UBJSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
from_ubjson(
    InputType&& i,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

create a JSON value from an input in UBJSON format

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
from_ubjson(
    IteratorType first,
    IteratorType last,
    bool const strict = true,
    bool const allow_exceptions = true);

Return Value

a class to store JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<typename T>
[[__warn_unused_result__, __deprecated__]]
static
basic_json
from_ubjson(
    T const* ptr,
    std::size_t len,
    bool const strict = true,
    bool const allow_exceptions = true);

returns the allocator associated with the container

Synopsis

Declared in <nlohmann/json.hpp>

static
allocator_type
get_allocator();

Return Value

the allocator type

wrapper to access iterator member functions in range‐based for

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
static
iteration_proxy<const_iterator>
iterator_wrapper(const_reference ref) noexcept;

Parameters

Name

Description

ref

the type of an element const reference

wrapper to access iterator member functions in range‐based for

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
static
iteration_proxy<iterator>
iterator_wrapper(reference ref) noexcept;

Parameters

Name

Description

ref

the type of an element reference

returns version information on the library

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
meta();

Return Value

a class to store JSON values

explicitly create an object from an initializer list

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__]]
static
basic_json
object(initializer_list_t init = {});

Return Value

a class to store JSON values

Parameters

Name

Description

init

helper type for initializer lists of basic_json values

Synopsis

Declared in <nlohmann/json.hpp>

[[__warn_unused_result__, __deprecated__]]
static
basic_json
parse(
    detail::span_input_adapter&& i,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

deserialize from a compatible input

Synopsis

Declared in <nlohmann/json.hpp>

template<typename InputType>
[[__warn_unused_result__]]
static
basic_json
parse(
    InputType&& i,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Return Value

a class to store JSON values

Parameters

Name

Description

per‐element parser callback type

deserialize from a pair of character iterators

Synopsis

Declared in <nlohmann/json.hpp>

template<typename IteratorType>
[[__warn_unused_result__]]
static
basic_json
parse(
    IteratorType first,
    IteratorType last,
    parser_callback_t cb = nullptr,
    bool const allow_exceptions = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

Return Value

a class to store JSON values

Parameters

Name

Description

per‐element parser callback type

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<typename SAX>
[[__deprecated__, __nonnull__]]
static
bool
sax_parse(
    detail::span_input_adapter&& i,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<
    typename InputType,
    typename SAX>
[[__nonnull__]]
static
bool
sax_parse(
    InputType&& i,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

generate SAX events

Synopsis

Declared in <nlohmann/json.hpp>

template<
    class IteratorType,
    class SAX>
[[__nonnull__]]
static
bool
sax_parse(
    IteratorType first,
    IteratorType last,
    SAX* sax,
    input_format_t format = input_format_t::json,
    bool const strict = true,
    bool const ignore_comments = false,
    bool const ignore_trailing_commas = false);

create a BJData serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_bjdata(
    basic_json const& j,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Parameters

Name

Description

a class to store JSON values

version

how to encode BJData

create a BJData serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bjdata(
    basic_json const& j,
    detail::output_adapter<uint8_t> o,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Parameters

Name

Description

a class to store JSON values

version

how to encode BJData

create a BJData serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bjdata(
    basic_json const& j,
    detail::output_adapter<char> o,
    bool const use_size = false,
    bool const use_type = false,
    bjdata_version_t const version = bjdata_version_t::draft2);

Parameters

Name

Description

a class to store JSON values

version

how to encode BJData

create a BSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_bson(basic_json const& j);

Parameters

Name

Description

a class to store JSON values

create a BSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bson(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Parameters

Name

Description

a class to store JSON values

create a BSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_bson(
    basic_json const& j,
    detail::output_adapter<char> o);

Parameters

Name

Description

a class to store JSON values

create a CBOR serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_cbor(basic_json const& j);

Parameters

Name

Description

a class to store JSON values

create a CBOR serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_cbor(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Parameters

Name

Description

a class to store JSON values

create a CBOR serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_cbor(
    basic_json const& j,
    detail::output_adapter<char> o);

Parameters

Name

Description

a class to store JSON values

create a MessagePack serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_msgpack(basic_json const& j);

Parameters

Name

Description

a class to store JSON values

create a MessagePack serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_msgpack(
    basic_json const& j,
    detail::output_adapter<uint8_t> o);

Parameters

Name

Description

a class to store JSON values

create a MessagePack serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_msgpack(
    basic_json const& j,
    detail::output_adapter<char> o);

Parameters

Name

Description

a class to store JSON values

create a UBJSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
std::vector<uint8_t>
to_ubjson(
    basic_json const& j,
    bool const use_size = false,
    bool const use_type = false);

Parameters

Name

Description

a class to store JSON values

create a UBJSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_ubjson(
    basic_json const& j,
    detail::output_adapter<uint8_t> o,
    bool const use_size = false,
    bool const use_type = false);

Parameters

Name

Description

a class to store JSON values

create a UBJSON serialization of a given JSON value

Synopsis

Declared in <nlohmann/json.hpp>

static
void
to_ubjson(
    basic_json const& j,
    detail::output_adapter<char> o,
    bool const use_size = false,
    bool const use_type = false);

Parameters

Name

Description

a class to store JSON values

an internal type for a backed binary type

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

template<typename BinaryType>
class byte_container_with_subtype
    : public BinaryType

Base Classes

Name

Description

BinaryType

Types

Name

container_type

subtype_type

Member Functions

Name

Description

byte_container_with_subtype [constructor]

Default constructor

byte_container_with_subtype [constructor]

Construct from container_type

byte_container_with_subtype [constructor]

Construct from container_type

byte_container_with_subtype [constructor]

clear_subtype

clears the binary subtype

has_subtype

return whether the value has a subtype

set_subtype

sets the binary subtype

subtype

return the binary subtype

operator==

Equality operator

operator!=

Inequality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

using container_type = BinaryType;

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

using subtype_type = uint64_t;

Default constructor

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype() noexcept(noexcept(container_type()));

Construct from container_type

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(container_type const& b) noexcept(noexcept(container_type(b)));

Parameters

Name

Description

The object to copy construct from

Construct from container_type

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(container_type&& b) noexcept(noexcept(container_type(std::move(b))));

Parameters

Name

Description

The object to move construct from

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(
    container_type const& b,
    subtype_type subtype_) noexcept(noexcept(container_type(b)));

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(
    container_type&& b,
    subtype_type subtype_) noexcept(noexcept(container_type(std::move(b))));

clears the binary subtype

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

void
clear_subtype() noexcept;

return whether the value has a subtype

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

constexpr
bool
has_subtype() const noexcept;

sets the binary subtype

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

void
set_subtype(subtype_type subtype_) noexcept;

return the binary subtype

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

constexpr
subtype_type
subtype() const noexcept;

Equality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

bool
operator==(byte_container_with_subtype const& rhs) const;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Inequality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

bool
operator!=(byte_container_with_subtype const& rhs) const;

Return Value

true if the objects are not equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

template<>
class byte_container_with_subtype<vector<unsigned char>>
    : public vector<unsigned char>

Base Classes

Name

Description

vector<unsigned char>

Types

Name

container_type

subtype_type

Member Functions

Name

Description

byte_container_with_subtype [constructor]

Constructors

Equality operator

Inequality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

using container_type = vector<unsigned char>;

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

using subtype_type = uint64_t;

Constructors

Synopses

Declared in <nlohmann/byte_container_with_subtype.hpp>

Default constructor

byte_container_with_subtype() noexcept(noexcept(container_type()));

Construct from container_type

byte_container_with_subtype(container_type const& b) noexcept(noexcept(container_type(b)));

Construct from container_type

byte_container_with_subtype(container_type&& b) noexcept(noexcept(container_type(std::move(b))));

byte_container_with_subtype(
    container_type const& b,
    subtype_type subtype_) noexcept(noexcept(container_type(b)));

byte_container_with_subtype(
    container_type&& b,
    subtype_type subtype_) noexcept(noexcept(container_type(std::move(b))));

Default constructor

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype() noexcept(noexcept(container_type()));

Construct from container_type

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(container_type const& b) noexcept(noexcept(container_type(b)));

Parameters

Name

Description

The object to copy construct from

Construct from container_type

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(container_type&& b) noexcept(noexcept(container_type(std::move(b))));

Parameters

Name

Description

The object to move construct from

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(
    container_type const& b,
    subtype_type subtype_) noexcept(noexcept(container_type(b)));

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

byte_container_with_subtype(
    container_type&& b,
    subtype_type subtype_) noexcept(noexcept(container_type(std::move(b))));

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

void
clear_subtype() noexcept;

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

constexpr
bool
has_subtype() const noexcept;

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

void
set_subtype(subtype_type subtype_) noexcept;

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

constexpr
subtype_type
subtype() const noexcept;

Equality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

bool
operator==(byte_container_with_subtype<vector<unsigned char>> const& rhs) const;

Return Value

true if the objects are equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Inequality operator

Synopsis

Declared in <nlohmann/byte_container_with_subtype.hpp>

bool
operator!=(byte_container_with_subtype<vector<unsigned char>> const& rhs) const;

Return Value

true if the objects are not equal, false otherwise

Parameters

Name

Description

rhs

The right operand

Synopsis

Declared in <nlohmann/json.hpp>

template<typename>
class json_pointer;

JSON Pointer defines a string syntax for identifying a specific value within a JSON document

Synopsis

Declared in <nlohmann/json_fwd.hpp>

template<typename RefStringType>
class json_pointer;

Friends

Name

Description

nlohmann::operator/

create a new JSON pointer by appending the array‐index‐token at the end of the JSON pointer

nlohmann::operator/

create a new JSON pointer by appending the unescaped token at the end of the JSON pointer

nlohmann::operator/

create a new JSON pointer by appending the right JSON pointer at the end of the left JSON pointer

nlohmann::operator<<

write string representation of the JSON pointer to stream

nlohmann::json_pointer

JSON Pointer defines a string syntax for identifying a specific value within a JSON document

nlohmann::basic_json

a class to store JSON values

a minimal map‐like container that preserves insertion order

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<
    class Key,
    class T,
    class IgnoredLess,
    class Allocator>
struct ordered_map
    : std::vector<std::pair<Key const, T>, Allocator>

Base Classes

Name

Description

std::vector<std::pair<Key const, T>, Allocator>

Types

Name

Member Functions

Name

Description

ordered_map [constructor]

Constructors

Subscript operators

Description

ordered_map: a minimal map‐like container that preserves insertion order for use within nlohmann::basic_json<ordered_map>

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using Container = std::vector<std::pair<Key const, T>, Allocator>;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using const_iterator = Container::const_iterator;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using iterator = Container::iterator;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using key_compare = std::equal_to;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using key_type = Key;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using mapped_type = T;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<typename InputIt>
using require_input_iter = void;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using size_type = Container::size_type;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

using value_type = Container::value_type;

Constructors

Synopses

Declared in <nlohmann/ordered_map.hpp>

Default constructor

ordered_map() noexcept(noexcept(Container()));

Construct from Allocator

explicit
ordered_map(Allocator const& alloc) noexcept(noexcept(Container(alloc)));

ordered_map(
    std::initializer_list<value_type> init,
    Allocator const& alloc = Allocator());

template<class It>
ordered_map(
    It first,
    It last,
    Allocator const& alloc = Allocator());

Default constructor

Synopsis

Declared in <nlohmann/ordered_map.hpp>

ordered_map() noexcept(noexcept(Container()));

Construct from Allocator

Synopsis

Declared in <nlohmann/ordered_map.hpp>

explicit
ordered_map(Allocator const& alloc) noexcept(noexcept(Container(alloc)));

Parameters

Name

Description

alloc

The object to copy construct from

Synopsis

Declared in <nlohmann/ordered_map.hpp>

ordered_map(
    std::initializer_list<value_type> init,
    Allocator const& alloc = Allocator());

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class It>
ordered_map(
    It first,
    It last,
    Allocator const& alloc = Allocator());

Synopses

Declared in <nlohmann/ordered_map.hpp>

T&
at(key_type const& key);

T const&
at(key_type const& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T const&
at(KeyType&& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T&
at(KeyType&& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

T&
at(key_type const& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

T const&
at(key_type const& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T const&
at(KeyType&& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T&
at(KeyType&& key);

Synopses

Declared in <nlohmann/ordered_map.hpp>

size_type
count(key_type const& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
size_type
count(KeyType&& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

size_type
count(key_type const& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
size_type
count(KeyType&& key) const;

Synopses

Declared in <nlohmann/ordered_map.hpp>

std::pair<iterator, bool>
emplace(
    key_type const& key,
    T&& t);

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
std::pair<iterator, bool>
emplace(
    KeyType&& key,
    T&& t);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

std::pair<iterator, bool>
emplace(
    key_type const& key,
    T&& t);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
std::pair<iterator, bool>
emplace(
    KeyType&& key,
    T&& t);

Synopses

Declared in <nlohmann/ordered_map.hpp>

iterator
erase(iterator pos);

size_type
erase(key_type const& key);

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
size_type
erase(KeyType&& key);

iterator
erase(
    iterator first,
    iterator last);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

iterator
erase(iterator pos);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

size_type
erase(key_type const& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
size_type
erase(KeyType&& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

iterator
erase(
    iterator first,
    iterator last);

Synopses

Declared in <nlohmann/ordered_map.hpp>

iterator
find(key_type const& key);

const_iterator
find(key_type const& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
iterator
find(KeyType&& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

iterator
find(key_type const& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

const_iterator
find(key_type const& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
iterator
find(KeyType&& key);

Synopses

Declared in <nlohmann/ordered_map.hpp>

std::pair<iterator, bool>
insert(value_type const& value);

std::pair<iterator, bool>
insert(value_type&& value);

template<
    typename InputIt,
    typename = require_input_iter<InputIt>>
void
insert(
    InputIt first,
    InputIt last);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

std::pair<iterator, bool>
insert(value_type const& value);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

std::pair<iterator, bool>
insert(value_type&& value);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<
    typename InputIt,
    typename = require_input_iter<InputIt>>
void
insert(
    InputIt first,
    InputIt last);

Subscript operators

Synopses

Declared in <nlohmann/ordered_map.hpp>

T&
operator[](key_type const& key);

T const&
operator[](key_type const& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T const&
operator[](KeyType&& key) const;

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T&
operator[](KeyType&& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

T&
operator[](key_type const& key);

Synopsis

Declared in <nlohmann/ordered_map.hpp>

T const&
operator[](key_type const& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T const&
operator[](KeyType&& key) const;

Synopsis

Declared in <nlohmann/ordered_map.hpp>

template<class KeyType>
requires detail::is_usable_as_key_type<key_compare, key_type, KeyType>::value
T&
operator[](KeyType&& key);

Synopses

Declared in <nlohmann/json.hpp>

[[__nonnull__]]
nlohmann::json
Unnamed function(
    char const* s,
    std::size_t n);

[[__nonnull__]]
nlohmann::json::json_pointer
Unnamed function(
    char const* s,
    std::size_t n);

Synopsis

Declared in <nlohmann/json.hpp>

[[__nonnull__]]
nlohmann::json
Unnamed function(
    char const* s,
    std::size_t n);

Synopsis

Declared in <nlohmann/json.hpp>

[[__nonnull__]]
nlohmann::json::json_pointer
Unnamed function(
    char const* s,
    std::size_t n);

Right shift operators

Synopses

Declared in <nlohmann/json.hpp>

deserialize from stream

std::istream&
operator>>(
    std::istream& i,
    basic_json& j);

deserialize from stream

std::istream&
operator>>(
    std::istream& i,
    basic_json& j);

serialize to stream

[[__deprecated__]]
std::ostream&
operator>>(
    basic_json const& j,
    std::ostream& o);

serialize to stream

[[__deprecated__]]
std::ostream&
operator>>(
    basic_json const& j,
    std::ostream& o);

deserialize from stream

Synopsis

Declared in <nlohmann/json.hpp>

std::istream&
operator>>(
    std::istream& i,
    basic_json& j);

Parameters

Name

Description

The left operand

The right operand

deserialize from stream

Synopsis

Declared in <nlohmann/json.hpp>

std::istream&
operator>>(
    std::istream& i,
    basic_json& j);

Parameters

Name

Description

The left operand

The right operand

serialize to stream

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
std::ostream&
operator>>(
    basic_json const& j,
    std::ostream& o);

Parameters

Name

Description

The left operand

The right operand

serialize to stream

Synopsis

Declared in <nlohmann/json.hpp>

[[__deprecated__]]
std::ostream&
operator>>(
    basic_json const& j,
    std::ostream& o);

Parameters

Name

Description

The left operand

The right operand

exchanges the values

Synopses

Declared in <nlohmann/json.hpp>

exchanges the values

void
swap(
    reference left,
    reference right) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

exchanges the values

void
swap(
    reference left,
    reference right) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(
    reference left,
    reference right) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

Parameters

Name

Description

left

the type of an element reference

right

the type of an element reference

exchanges the values

Synopsis

Declared in <nlohmann/json.hpp>

void
swap(
    reference left,
    reference right) noexcept(std::is_nothrow_move_constructible<value_t>::value && std::is_nothrow_move_assignable<value_t>::value && std::is_nothrow_move_constructible<json_value>::value && std::is_nothrow_move_assignable<json_value>::value);

Parameters

Name

Description

left

the type of an element reference

right

the type of an element reference

user‐defined to_string function for JSON values

Synopsis

Declared in <nlohmann/json.hpp>

template<
    template<
    typename,
    typename,
    typename...> typename ObjectType,
    template<
    typename,
    typename...> typename ArrayType,
    class StringType,
    class BooleanType,
    class NumberIntegerType,
    class NumberUnsignedType,
    class NumberFloatType,
    template<typename> typename AllocatorType,
    template<
    typename,
    typename = void> typename JSONSerializer,
    class BinaryType,
    class CustomBaseClass>
std::string
to_string(basic_json<ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType, CustomBaseClass> const& j);

Parameters

Name

Description

a class to store JSON values

Left shift operators

Synopses

Declared in <nlohmann/json.hpp>

deserialize from stream

[[__deprecated__]]
std::istream&
operator<<(
    basic_json& j,
    std::istream& i);

serialize to stream

std::ostream&
operator<<(
    std::ostream& o,
    basic_json const& j);

write string representation of the JSON pointer to stream

std::ostream&
operator<<(
    std::ostream& o,
    json_pointer const& ptr);

[» more...]

deserialize from stream

[[__deprecated__]]
std::istream&
operator<<(
    basic_json& j,
    std::istream& i);

serialize to stream

std::ostream&
operator<<(
    std::ostream& o,
    basic_json const& j);